#-*-coding=utf-8-*-
#--------------------------------------------------------------
# Author: baojiangfeng
# Email: baojiangfeng@qiyi.com
# Creation Date: 2021-01-28
# Last Modified: 2021年02月02日 星期二 19时49分04秒
# Description:
# Usage:
#--------------------------------------------------------------

from collections import Counter

c = Counter()
with open("PARADE_test.txt","r") as f:
    data = f.readlines()
n = 0
for idx, line in enumerate(data):
    if idx == 0:
        continue
    line = line.strip().split("\t")
    s1 = line[3]
    s2 = line[4]
    c[s1]+=1
    c[s2] +=1
print(len(c.keys()))
